The present invention relates to assemblies that have two or more clamped components that are clamped together by a fastener assembly. In such assemblies, one or more of the two or more clamped components defines through itself a fastener hole. The fastener assembly that clamps the two or more clamped components together comprises a fastener shaft that extends through the fastener hole. The fastener assembly, further comprises two clamping structures each of which extends radially outwardly from the fastener shaft in directions perpendicular to an axis of the fastener shaft and each of which is spaced relative to the other in directions parallel to the axis of the fastener shaft. Portions of the two or more clamped components are clamped between the two clamping structures of the fastener assembly. There are many different well-known types of fastener assemblies that can function in such a way to clamp two or more clamped components together including but not necessarily limited to threaded fasteners (such as bolts and nuts), rivets, and swaged-collar fasteners such as those illustrated in U.S. Pat. No. 5,604,968 to Huck Patents, Inc. which patent is incorporated herein by reference. For purposes of this disclosure swaged-collar fasteners will be considered to be any fastener such as those illustrated in U.S. Pat. No. 5,604,968 or similar thereto in that they comprise some type of fastener shaft with a clamping structure at one end and a clamping collar which constitutes the other clamping structure of the fastener and which is secured to the fastener shaft by plastically deforming the collar until it has an interference fit with the fastener shaft.
The magnitude of the clamping force applied to two or more clamped components by a fastener assembly that clamps the clamped components together is important. In most applications of fastener assemblies it is preferred that two or more clamped components that are clamped together by a fastener assembly are clamped with sufficient force to prevent them from slipping relative to one another. Unfortunately, for many types of fastener assemblies, including rivets and swaged-collar fasteners, there is no known way to ascertain, even approximately, what magnitude of clamping force is applied to two or more clamped components that are clamped together by the fastener assembly.